Exciting Your Instrument Without Moving Air

Here’s an interesting video put together by Dr. Richard Smith, a scientist, musician, and instrument maker. In this video he demonstrates something that seems counterintuitive – you don’t have to blow air through the instrument in order for it to function normally.

A few years ago I had heard about this experiment and tried to recreate it. I drilled a hole through the cup of an old mouthpiece and tried setting up the membrane to block the air from going through. It didn’t work. Later I came across his technical paper on the topic and learned that I needed to set the membrane up before the shank of the mouthpiece. But it looks like what is really important was to set up a “shank” that directs the air out of the mouthpiece and instrument.

It was almost impossible to get the lips to vibrate under these conditions of using a small side hole. However, a solution was found by comparing this acoustical problem with the electrical analogy of a.c./d.c. decoupling – as used in most electronic circuits. This shows that a resistance is needed for the d.c. flow to occur. To provide this resistance acoustically, a narrow tube was placed in the side hole to give enough air resistance for the lips to vibrate against and to enable sustained vibration.

Maybe I will have to go back and find that old mouthpiece and see if I can set it up correctly and try it out. It would take more skill (and the proper tools) than I currently possess, but I have a couple of friends that would probably be interested enough in goofing around with it to give me a hand.

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I came across this video on an online forum devoted to brass pedagogy. Some of the ensuing comments bugged me. Here are some actual quotes from that forum.

He is right. Air does not have to travel through the tube. Unfortunately we have a tough time wiggling our lips back and forth 200 and more times per second. I just tried it. Nope. Wait. About 6 per second just now.

While this is perhaps a legitimate consideration for the purpose of teaching brass technique, it’s really a straw man complaint. In his video Smith in fact goes out of his way to explicitly state that air is needed to set the lips to vibrate, but the point of his demonstration is the fact that once the air passes the lips there’s no physical law that the air needs to actually move through the instrument in order for it to work normally.

Just because you and I can’t think of an immediate pedagogical application of Smith’s demonstration doesn’t mean that there isn’t one.

What would be massively helpful is if he didn’t sound like trash doing it the way we all do it.

Again, the complaint here does have a bit of validity, but this too is irrelevant to the intention of Smith’s demonstration video. As best as I can tell, Smith’s background is mainly in acoustics and instrument design and construction. For all I know his main instrument may not be any of the instruments he is demonstrating in this video. He may be too busy building instruments and researching acoustics to do much practice these days. In no way does his ability to play a brass instrument negate the factual statements he makes.

Purely pointless IMHO.

Personally, I feel that being this dismissive is a shame coming from a teacher. Teachers are supposed to inspire curiosity and creative thinking. The point I made above about not passing judgement just because we don’t think of an immediate relevance to teaching brass applies here. But more importantly, discouraging students from exploring this video also dissuades students from learning about topics other than music. I’ve had and have students who have no intention of going into music as a career path, and some who have even been physics majors. I wonder how one of those students would feel to find me disparaging a factually correct demonstration of acoustics like this.

But if you need some practical applications, you don’t have to look very far. Simply pay close attention to what Smith says in his video. He mentions how without needing to blow air through the instrument you wouldn’t need a spit valve or need to clean the instrument out regularly. In the paper Smith recalls how research into the a.c./d.c. effect of brass acoustics has influenced the way in which instruments were tested for design and construction faults.

Pedagogical applications of this research are a little harder to think of, but not impossible. One could use the altered mouthpiece sort of like running with small weights strapped to your wrists and feet. Playing exercises or music would require more effort and could potentially be useful for advanced players to build playing endurance. Another thought I had was that if the mouthpiece could be tweaked enough so that it played similarly enough to playing the instrument normally one could design an almost perfectly silent practice mute. Practice mutes tend to be very stuffy and while that can be used in a manner similar to what I just mentioned, it makes relying on a practice mute for long term practice less ideal. Imagine a combination of a practice mute with this type of mouthpiece so that it would feel almost like playing with an open horn while being quiet enough to practice late at night in a hotel room.

Here’s an excerpt from a much longer response to Smith’s demonstration video.

Gotta love these quacks.

There are SO MANY OF THEM!!!

Whadda waste of time!!!

Whadda buncha MAROONS!!!

*sigh*

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